Portion of a light bulb



FIG. 1 is a perspective view of a portion of a light bulb showing an embodiment of my new design;

FIG. 2 is a front view of the embodiment;

FIG. 3 is a rear view of the embodiment;

FIG. 4 is a left side view of the embodiment;

FIG. 5 is a right side view of the embodiment;

FIG. 6 is a top view of the embodiment; and,

FIG. 7 is a bottom view of the embodiment.

The broken line portions of a portion of a light bulb in FIGS. 1-7 represent unclaimed portions of the design and form no part thereof. 

CLAIM The ornamental design for a portion of a light bulb, as shown and described. 